Currently, an inter-base station carrier aggregation technology is introduced in a Long-Term Evolution Advanced (LTE-A) system. The inter-base station carrier aggregation technology may also be referred to as a dual-connectivity technology. In the dual-connectivity technology, because data transmission between two base stations that perform carrier aggregation is non-ideal backhaul, start moments of downlink subframes sent by the two base stations to user equipment (UE) may be asynchronous (which is an asynchronous dual-connectivity scenario), that is, there may be any time difference between the start moments of the downlink subframes of the two base stations. In addition, each base station may receive uplink subframes corresponding to multiple different timing advance groups (TAGs). Therefore, there may also be any time difference between start moments of uplink subframes sent by the UE to the two base stations, that is, there may be an overlapping time between these uplink subframes. The overlapping time is a non-fixed value. A TAG is a cell group, and uplink transmission channels of UE in cells of the group have same timing. If cells of two channels belong to a same TAG, the two channels have a same uplink transmission timing advance, and the two channels have same uplink transmission timing. Different TAGs have different timing advances, and therefore, each TAG may have different uplink transmission time.
In some approaches, in the foregoing asynchronous dual-connectivity scenario, before the UE sends the uplink subframes to the two base stations, the UE needs to allocate transmit power to uplink channels in the uplink subframes, so as to implement data transmission between the UE and the two base stations. There are overlapping time between multiple uplink subframes, and the overlapping time is a non-fixed value; therefore, when allocating transmit power to an uplink channel that is in a TAG of a base station and in an uplink subframe, the UE needs to consider transmit power of uplink channels that are in all TAGs of the two base stations and that are in all uplink subframes having overlapping time with the uplink subframe.
However, when allocating transmit power to an uplink channel that is in a TAG of a base station and in the uplink subframe, the UE needs to consider the transmit power of the uplink channels that are in all the TAGs of the two base stations and that are in all the uplink subframes having overlapping time with the uplink subframe. Therefore, in an asynchronous dual-connectivity scenario, the UE allocates, by using an extremely complex solution, the transmit power to the uplink channel that is in the TAG of the base station and in the uplink subframe, which causes a relatively large implementation difficulty.